The present invention relates to a method of textile printing by microorganism and a microorganism for decolorization of azo system dye. More specifically, the present invention relates to a textile printing method using a specific bacterium, comprising treating a base material colored with an azo-system dye or with a azo-system dye together with a non azo-system dye or a base material with a pattern printed thereon by means of a paste solution containing at least the specific bacterium (and another azo-system dye). Additionally, the present invention also relates to a microorganism for decoloring azo system dyes. The microorganism being capable of metabolizing the azo system dyes.
The term "textile printing" includes direct textile printing (printing a pattern on a white base material or a ground dyed base material), discharge printing printing a pattern on a ground dyed base material (including white discharge printing, colored discharge printing and semi-discharge printing)! and reserve printing (comprising dyeing after drawing a pattern with a substance inhibiting the dyeing).
For the "discharge printing" , there is carried out 1. "white discharge printing" comprising depositing a paste solution containing a reducing agent or an alkali on primarily solid dyed cloth following a desired pattern for thermal processing, to facilitate decolorization via the reduction or the saponification of the carboxylate of a dispersion dye, thereby producing the pattern in white; 2. so-called "colored discharge printing" comprising effecting bleaching along with dyeing with another color; and 3. "semi-discharge printing" comprising terminating the white discharge printing during its intermediate stage, thereby leaving a pattern in slightly paler color than the base color. Furthermore, the "direct textile printing" comprises coating (printing, etc.) a given pattern on a base material using a predetermined color paste, subsequently drying the material, and steaming and washing the material for final finishing.
According to the aforementioned textile printing methods (the color discharge printing in particular), a reducing agent or an alkali is used for bleaching, so that it is required that the dye for preliminary solid dyeing (so-called dye for ground dyeing) should be a dye which can be decolored readily. Furthermore, the textile printing is limited in that the printing dye (dye of effect color for printing) should he a dye resistant to reduction and alkalis during decolorization. The textile printing is disadvantageous in that cloth may be damaged with reducing agents and that halation (blurring in the border of colors) may occur readily.